The invention relates to a treated, especially painted, sandwich, in which at least two parts to be joined are fixed reversibly, with the formation of a spaced joint.
For the treatment, especially painting, various means are known of fixing, protecting or masking the individual parts during the procedure.
For instance, self-adhesive masking tapes are on the market whose purpose is to protect areas that are not to be painted, but which have the disadvantage of sharp paint edges at the transition from unpainted to newly painted regions.
Circular foam strips in accordance with U.S. Pat. No. 5,260,097 have been proposed as an improvement on this and in the case of spray painting are intended to lead to a situation in which xe2x80x9cthe border forming the transition between the cushion which has just been removed and the treated surface can no longer be seenxe2x80x9d(col. 5, lines 59-61). A fixing aid or the like, however, is not possible with such an arrangement.
DE 86 07 368 U1 discloses a masking tape made, in particular, of foamed material, having a projecting lip which guides the spray mist during painting in such a way that it xe2x80x9cleads to a uniform, i.e. stepless transition between the old and the new coat of paintxe2x80x9d(p. 1, lines 9/10 from bottom). With this tape, a further self-adhesive composition can be arranged on the top side so that masking material with a large expanse can be attached to it. Here again, fixing of further parts to be joined is possible only inadequately if at all.
However, in order to treat, and especially to paint, firmly fixed joined parts in such a way that, by virtue of a spaced joint, the results of treatment are free from transition in the adjacent, marginal regions, complex fixing is necessary-for instance, by means of screws, clamps, vices for brackets or brackets, which have to be removed again once treatment has taken place, which is laborious and also awkward. An elegant solution to such problems remains open.
The object of the invention was to remedy this situation and, in particular, to create a reversible fixing for parts to be joined, with a spaced joint, which in the course, for example, of spray painting gives rise to a smooth paint edge which does not require subsequent work.
This object is achieved by means of a sandwich as characterized in detail in the claims.
Particularly suitable adhesive films are those in accordance with DE 33 31 016, DE 42 22 849, DE 42 33 872, WO 92/11333 and WO 94/21157.
Thus DE 33 32 016 A1 describes an adhesive film for temporary adhesive bonds which allows an adhesive bond produced therewith to be separated by pulling on the adhesive film in the direction of the bond plane. Adhesive films of this type allow high bond strengths and shear strengths to be achieved and allow adhesively bonded assemblies to be separated again without further means, in a manner comparable to the opening of a preserving jar, similarly to how, in that case, the rubber seal is pulled by the grip tab out of the sealing join.
DE 42 22 849 C1 describes an adhesive film of this kind having a UV-permeable grip tab.
In addition, WO 92/11333 describes, inter alia, adhesive films for corresponding applications, where the adhesive films employed combine low elasticity with high extensibility.
In accordance with the invention it is also possible to employ double-sided self-adhesive tapes with a foam middle support made, for example, from polyethylene foam.
Regarding preparation, processing and handling of the particularly preferred adhesive films, general reference may be made to DE 33 31 016, DE 42 22 849 and WO 92/11333.